TRACE ELEMENTS DISTRIBUTION IN HEIRLOOM PADDY PANDASAN CULTIVATED UNDER FIELD CONDITIONS OF DRY AND WET SOIL

Abstract

Trace elements phytoavailability depends on the physical and chemical properties
of soil. At the Crocker range of West Coast Sabah, Malaysia, the Pandasan paddy
variety can be cultivated as flooded rice paddies or upland rice on acidic soil.
Pandasan paddy samples were collected in Kiulu subdistrict from traditional
farmer at two different locations. Available sources of trace elements were from
weathering, fertilizers and pesticides. Soil and plant samples were collected after
two months of seed sowing and during harvest season which was five months old
for heavy metal analysis by inductively coupled plasma optical emission
spectrometry (ICP-OES). Translocation factor of arsenic from root to grain
indicated this trace element was very mobile in Pandasan paddy cultivated at dry
soil compared to wet soil followed by zinc. Although, cadmium was not detected in
paddy cultivated at flooded field for both, soil and plant, cadmium was detected in
soil and plant roots cultivated in dry condition. Enrichment factor results suggested
that Pandasan plant cultivated on dry soil was only a good bioindicator for lead
and zinc. Pandasan grain was rich with iron followed by zinc. Selected heavy
metals accumulation in Pandasan grain cultivated in flooded field did not exceeded
the permissible limit of Malaysia Food Regulation 1985. However arsenic and
plumbum concentration in Pandasan grain harvested from dry soil exceeded the
permissible limit of Malaysia Food Regulation 1985. Health risk of heavy metals
toxicity can be reduced if Pandasan paddy is cultivated in flooded field compared
to dry soil.